import java.util.*;

//@Invariant("connectedToDB()")
public interface DatabaseInterfaceC{
	
//	@Requires("{!userTableEmpty(), userSet()}")
	//String getUser();
	
//	@Requires("!userTableEmpty()")
	String[] getAllUsers();
	
//	@Ensures("!userTableEmpty()")
	void addUser(String userName);
	
//	@Ensures("userSet()")
	//void setUser(String user);
	
//	@Requires("!coasterTableEmpty()")
	String[] getAllRollercoasters();
	
//	@Ensures("!coasterTableEmpty()")
	void saveRollerCoaster(String coasterName, ArrayList<ArrayList<double[]>> rCoaster);
	
	void getRollerCoaster(String coasterName);
	
	boolean userTableEmpty();
	boolean coasterTableEmpty();
	boolean connectedToDB();
		
}